The invention concerns an SCR exhaust gas aftertreatment device designed to protect against freezing damage.
An SCR exhaust gas aftertreatment device is already known from DE 10 2008 012 780 A1. In it, a urea-water solution is injected into an exhaust gas line. A pump unit with a pressure filter is provided to produce the pressure needed for injecting the urea-water solution. This pressure filter lies in the area of an internal space of the pump unit. A compressible equalization element is also arranged on the pump unit. However, this equalization element does not lie in the area of the pressure filter.
The urea-water solution is abbreviated UWS hereafter.
Furthermore, filters for a UWS are known from DE 102 20 662 B4 and DE 102 20 672. These filters are structurally designed for expansion upon freezing of the UWS.
DE 103 62 140 B4 concerns an extension part made from an elastomer material, which yields when freezing UWS expands.